Most centers should provide single rooms ideally n single cell pagoda for meditation...I did a few courses, n they all had single n 2 per room accommodation...Am 100 % sure they will provide single room if u tell them your situation .....Also very important to talk to the teacher exactly what you are going through now... Taking medication if I was highly anxious was useful in the beginning.its difficult but not impossible, I used to meditate alone when I was anxious... That helps if u r scared of company...Only 3 group sittings, others u can manage in cell/room and walking too. Doing in a relaxed way was the key to me.feel free to ask me anything about this.